Is there an ongoing issue with Mercedes power units?

17:56, 28 May

bySavannah Lenz

Bradley Lord, a Mercedes team representative, was the guest of the week on their 2025 Monaco GP F1 Akkodis Race Debrief. He explained what happened to George Russell in Monaco and whether it would happen again in Barcelona.

After explaining that Mercedes made set up changes for qualifying after Russell struggled in practice sessions, Lord mentioned his performance in Q2, “The performance indication was good.Then suddenly he lost power. He came on the radio, said, got no power, got no drive.”

Russell was improving during qualifying, and if his car had not given out, his chances of making it into Q3 would have been high. Mercedes has had a good track record of qualifying this season.

Unfortunately, Russell's car stopped and had to be taken back to the garage. This left him starting in 14th place.

Lord explained what happened saying, “It transpires that what has happened is that a wiring loom has short-circuited and that has cost ignition power to the combustion engine.”

“George, for the next part of the lap, was able to motor on the electric motor. So the MGU-K is draining down the energy that was in the battery. But then that also ran out in the tunnel. So ultimately, an electrical problem, a short circuit in a wiring loom that led to a failure of the ignition electrics on the engine.”

To stop it from happening in Barcelona, Lord said, “In terms of resolving that, we've been able to identify what's happened. We'll be able to countercheck all of the other PUs that are in the pool to make sure that there isn't any imminent danger of a repeat.”